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Electric Exige?? (Dale Vince - Wind Car)

Discussion in 'Electric Conversions' started by doug, May 19, 2008.

  1. doug

    doug Administrator / Head Moderator

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    #21 doug, Jan 6, 2009
    Last edited: Jan 6, 2009
    That's exactly what I mean by, "dual rear motor setup with an independent belt drive to each wheel." Two motors, two belts, two drive wheels. Sorry if I wasn't clear enough. By "function of a differential when the car makes a turn," I mean that the outer rear wheel needs to spin faster than the inner rear wheel. You need to control for that since you don't have a mechanical system to do that for you. You actually have to tell that outer wheel how much faster to spin.

    If not monitoring the individual wheel speed, I suppose you could look at the electrical load on each motor. You could then use feedback to balance the load between the two motors... that's essentially what an open differential does anyway. Not certain if that's the right algorithm in this case, though. If you're smart about it, you could make an effective LSD. At any rate, once you solve that control problem, seems you have half a TC system.
     
  2. TEG

    TEG TMC Moderator

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    I think I got your point and you may have missed mine.

    Or my point may be wrong.

    In any case, I think with Tesla's AC motor they are controlling _exactly_ how quickly the motor spins. They have to create A/C waveforms precisely matched to motor RPMs. With a DC motor it is more of just "give it current and let it spin as fast it wants to". So with dual DCs if you round a corner and one wheel wants to spin at a different rate (since it is trascribing a different arc) then it is OK as one motor speeds up a bit and the other slows down. I don't think (but I could be wrong) that they need any special "simulated differential" electronics to do that. Now the effect may be something akin to "open differential" where you run into traction issues if one wheel is on a slippery surface. That is possibly one reason why the home brew person looking for shortcuts would use a simple dual DC motor setup, and a more sophisticated operation would use a single AC motor with a differential and torque limiting traction control.

    It is a lot easier to design an EV that works OK in good conditions, but when you want something that is "user friendly" in all conditions (including on snow and ice) you have to do a lot more work.
     
  3. doug

    doug Administrator / Head Moderator

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    #23 doug, Jan 6, 2009
    Last edited: Jan 6, 2009
    Yeah, ya know I read right past the DC distinction you were making since it seemed you missed I was already talking about dual belts.
    I don't know what kind of motors they're using in the "wind car." I assumed they were brushless DC motors, which can allow for fine speed control. I just assumed each motor has it's own controller. (This is what I'd prefer they'd talk about rather than body work.)

    Yeah, I guess if you used two standard DC motors wired in parallel from the same supply, the reduced load on the outer wheel would cause it to spin faster, making a kind of simulated open differential.




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  4. doug

    doug Administrator / Head Moderator

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    #24 doug, Jan 8, 2009
    Last edited: Jan 8, 2009
    It occurred to me that I should have said wired in series.





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  5. dpeilow

    dpeilow Moderator

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  6. doug

    doug Administrator / Head Moderator

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    #26 doug, Jan 9, 2009
    Last edited by a moderator: Mar 13, 2016
    Ahh British idioms... Is that like few pence short of a shilling?
    I can't tell if you're saying he lost some money, or if he's nuts, or both.




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  7. dpeilow

    dpeilow Moderator

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    Just the former. I'm sure he's completely sound of mind...
     
  8. doug

    doug Administrator / Head Moderator

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    #28 doug, Jan 14, 2009
    Last edited by a moderator: Mar 13, 2016
  9. malcolm

    malcolm Active Member

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    "99% of all UK road journeys are under 100 miles"

    I think the figure for the US was 200 miles.
     
  10. TEG

    TEG TMC Moderator

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    Tesla & PBP seem to be pursuing that idea, but there are still plenty who question if it is ultimately the right answer.

    By the way, that was a good interview, but I have trouble getting past the idea that Tesla has already "stole" much of Vince's thunder. His viewpoints would have seemed more fresh a few years ago.
     
  11. doug

    doug Administrator / Head Moderator

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    #31 doug, Jan 16, 2009
    Last edited: Jan 17, 2009
    Yeah, you're totally right. I'm not sure I much see the point of his exercise. But I have no problem with him doing it. I just wish they gave more technical details that I would find interesting. What I'm struck by in the video is that, given what he is doing, he doesn't seem that knowledgeable about what's going on in the world of EVs.

    He makes a point of taking a few jabs at Tesla. He mentions that a Tesla PR guy (it was Darryl) left a note on his blog that he should just buy a Roadster. Dale said he wanted a test drive, but that the PR guy never responded. This is at least the third time I've seen him relate that story (in print or in a video). Perhaps someone from Tesla should follow up with him.

    He says that the Wind Car will have better handling than the Exige. I find that hard to imagine.
     
  12. TEG

    TEG TMC Moderator

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    He also said he was talking to Lotus about the electric Elise idea but then Tesla came along. More sour grapes perhaps... I guess he has been working on this idea for a while, and then Tesla jumped in and ran with it more quickly than he was.

    Anyways, the guy seems to have done quite well by himself selling wind generators as a good business, and I hope he has fun with his car project, regardless of what anyone else is doing.
     
  13. dpeilow

    dpeilow Moderator

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    Just by way of closing out this story:

    UFO ruled out of wind farm prang ? The Register

     
  14. doug

    doug Administrator / Head Moderator

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    #34 doug, Feb 16, 2009
    Last edited: Feb 16, 2009
    It wasn’t ET ‘wat done it’ | Energy | Zerocarbonista

    So it fell apart on it's own. That's a tad concerning. Good thing no one was around.
     
  15. doug

    doug Administrator / Head Moderator

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    #35 doug, Feb 16, 2009
    Last edited by a moderator: Mar 13, 2016
    New wind car episode:

    The Wind Car (5 of 6) | Transport | Zerocarbonista


    The gist of this installment is basically that they have a lot more to do, actually had to redo some stuff, and are maybe just now at the half way point. It's disappointing in that is doesn't show any progress or at even talk about anything interesting. Just several shots of a CNC machining some aluminum. Again I'd prefer they talked more about the drivetrain.
     
  16. doug

    doug Administrator / Head Moderator

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    #37 doug, Feb 18, 2009
    Last edited by a moderator: Mar 13, 2016
    From the site:
    That was clear from part 4, when he first said it would be 6 parts.
    I actually think this is a good name for a product from an eccentric Brit.
    [​IMG]
    Oh behave....



    The video this time actually has a little more substance. There finally are some reasonable shots of a few drivetrain components. Unfortunately they don't bother to discuss them. Instead, most of the video is spent talking about hydrogen fuel cells, responding to that controversial Top Gear episode.

     
  17. doug

    doug Administrator / Head Moderator

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    #38 doug, Feb 18, 2009
    Last edited: Feb 18, 2009
    Back in the Part 1 video, at one point there was a CAD drawing on a computer screen in the background that led me to believe they are using a belt drive. I've since been unable to find that shot (I think it's now intentionally blurred out). Anyway, this latest video shows the belts. We also see that they're using UQM brushless motors.

    3290796050_4898a471b7_o.jpg
    3289977973_255ced00a8_o.jpg 3289977957_8b11747c06_o.jpg
    3289978077_2dbbfc693f_o.jpg

    One detail on Dale's blog:
    I think that likely means they have to make a few design changes and remachine the transmission.
     
  18. doug

    doug Administrator / Head Moderator

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    Some shots of the chassis and battery compartment:

    3289977995_bbf14073e9_o.jpg
    3289978043_458ebe09e8_o.jpg
    3290796118_994c2bf516_o.jpg
     
  19. dpeilow

    dpeilow Moderator

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    I suppose you could say that one big battery box is much like any other, but that does look quite ESS-like...
     

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